Architecture &AMP; Engineering

Best in State: Gold award Social/economic sustainability

Power-generating infrastructure
at Snoqualmie Falls was upgraded as part of a three-year, $200
million redevelopment.

Kleinfelder

Project: Snoqualmie Falls hydroelectric redevelopment

Client: Puget Sound Energy

Puget Sound Energy is Washington’s largest private utility, serving over 1.9 million customers. The Snoqualmie Falls hydropower redevelopment project is a three-year, $200 million program that provides power to 40,000 customers.

The project included substantial upgrades to the power-generating infrastructure, development of a museum, relocation and renovation of six historical buildings, and major enhancements to the recreational facilities at Snoqualmie Falls and along the Snoqualmie River.

The project also added significant public access and amenities to one of the Pacific Northwest’s most scenic destinations, which receives 1.5 million to 2 million visitors annually.

The redevelopment included demolishing, expanding and rebuilding the world’s first completely underground powerhouse. The cavern containing this historical powerhouse built in 1898 is accessible via a vertical shaft that was hand-drilled and blasted through 294 feet of basalt bedrock.

A second, larger power-generation system originally built in 1910 required demolition and redevelopment of a traditional powerhouse that receives water via a 1,500-foot tunnel and multiple large-diameter high-head penstocks. Servicing both powerhouses are run-of-the-river intake structures and a low-head dam. The intake structures had to be demolished and then rebuilt in and adjacent to the Snoqualmie River, as well as above and below Snoqualmie Falls.

Kleinfelder provided construction-management services, including comprehensive quality assurance, geotechnical and rock engineering support, materials engineering and testing, and a number of quality-control services.